!-------------------------------------- LICENCE BEGIN ------------------------------------
!Environment Canada - Atmospheric Science and Technology License/Disclaimer,
! version 3; Last Modified: May 7, 2008.
!This is free but copyrighted software; you can use/redistribute/modify it under the terms
!of the Environment Canada - Atmospheric Science and Technology License/Disclaimer
!version 3 or (at your option) any later version that should be found at:
!http://collaboration.cmc.ec.gc.ca/science/rpn.comm/license.html
!
!This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
!without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
!See the above mentioned License/Disclaimer for more details.
!You should have received a copy of the License/Disclaimer along with this software;
!if not, you can write to: EC-RPN COMM Group, 2121 TransCanada, suite 500, Dorval (Quebec),
!CANADA, H9P 1J3; or send e-mail to service.rpn@ec.gc.ca
!-------------------------------------- LICENCE END --------------------------------------
!
!
! X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X
!
subroutine pc2UVg_c(pum,pvm,psi,chi) 2,6
!
!**s/r pc2UVg_c - Compute gridpoint wind images (U,V) from gridpoint (psi,chi)
!
!Author : Luc Fillion - CGD/NCAR - 7 sept 99
!Revision: Luc Fillion - MSC/CAN - 15 oct 2004 -GEM Arakawa-C grid.
!
! -------------------
!* Purpose: To build gridpoint analysis increments during 4D-Var.
!
!Arguments
!
IMPLICIT NONE
#include "taglam4d.cdk"
#include "pardim.cdk"
#include "comdim.cdk"
#include "comgrd_param.cdk"
#include "comcst.cdk"
#include "comct0.cdk"
#include "comsim.cdk"
#include "comgemla.cdk"
!
real*8 pum(0:ni+1,nflev,0:nj+1)
real*8 pvm(0:ni+1,nflev,0:nj+1)
real*8 psi(ni,nflev,nj)
real*8 chi(ni,nflev,nj)
!
integer ji,jj,jk,idim,idum1,idum2,idum3,idum4
integer ip1,jp1
INTEGER myid,numthd,omp_get_thread_num,omp_get_num_threads
real*8 zdlon,zdx,ztheta,ztheta1,zmin,zmax
real*8 zcos2(0:nj+1),zcos2h(0:nj+1)
real*8 zpsi(-1:ni+2,nflev,-1:nj+2)
real*8 zchi(-1:ni+2,nflev,-1:nj+2)
!
!!
idim=(ni+2)*(nj+2)*nflev
call zero
(idim,pum)
call zero
(idim,pvm)
!
ip1=ni+4
jp1=nj+4
idim=ip1*jp1*nflev
call zero
(idim,zpsi)
call zero
(idim,zchi)
!
zdlon=rdlon_an(1,1)
zdx=1./(ra*zdlon)
!
do jj=0,nj+1
zcos2(jj)=r1mmu2(jj)/(ra*rdmuh(jj-1))
zcos2h(jj)=r1mmu2h(jj)/(ra*rdmu(jj))
enddo
!
! symmetrize
!
call symmetrize
(zpsi,psi,ni,nj,nflev)
call symmetrize
(zchi,chi,ni,nj,nflev)
!
! Compute Wind-Images
!
!$OMP PARALLEL PRIVATE(ji,jj,jk,myid,numthd)
myid=omp_get_thread_num()+1
numthd=omp_get_num_threads()
do jk = myid,nflev,numthd
do jj=1,nj+1
do ji=0,ni
pum(ji,jk,jj)=zdx*(zchi(ji+1,jk,jj)-zchi(ji,jk,jj))
& -zcos2(jj)*( zpsi(ji,jk,jj)-zpsi(ji,jk,jj-1) )
enddo
enddo
!
do jj=0,nj
do ji=1,ni+1
pvm(ji,jk,jj)=zcos2h(jj)*(zchi(ji,jk,jj+1)-zchi(ji,jk,jj))
& +zdx*( zpsi(ji,jk,jj)-zpsi(ji-1,jk,jj) )
enddo
enddo
enddo
!$OMP END PARALLEL
!
return
end